WASHINGTON (AP) -- Huge increases in deportations of people after they were arrested for breaking traffic or immigration laws or driving drunk helped the Obama administration set a record last year for the number of criminal immigrants forced to leave the country, documents show.

The U.S. deported nearly 393,000 people in the fiscal year that ended Sept. 30, half of whom were considered criminals. Of those, 27,635 had been arrested for drunken driving, more than double the 10,851 deported after drunken driving arrests in 2008, the last full year of the Bush administration, according to Immigration and Customs Enforcement data provided to The Associated Press.

An additional 13,028 were deported last year after being arrested on less serious traffic law violations, nearly three times the 4,527 traffic offenders deported two years earlier, according to the data.

The spike in the numbers of people deported for traffic offenses as well as a 78 percent increase in people deported for immigration-related offenses renewed skepticism about the administration's claims that it is focusing on the most dangerous criminals.

President Barack Obama regularly says his administration is enforcing immigration laws more wisely than his predecessor by focusing on arresting the "worst of the worst." He promised in his 2008 presidential campaign to focus immigration enforcement on dangerous criminals. As recently as May 10, Obama said in a speech in El Paso, Texas, that his administration was focused on violent offenders and not families or "folks who are looking to scrape together an income."

Most of the criminal immigrants deported last year had committed drug-related crimes. They totaled 45,003, compared with 36,053 in 2008. Drug-related crime - described as the manufacture, distribution, possession or sale of drugs - has been the No. 1 crime among immigration for years. Drunken driving had the third highest total number of immigrants deported with that crime.

An illegal immigrant from Bolivia, Carlos Montano, is awaiting trial in Virginia on charges of involuntary manslaughter in a drunken driving accident that killed Benedictine nun Denise Mosier and injured two other nuns. The case fueled national debate over deportations of criminal immigrants because Montano had two previous drunken driving arrests, in 2007 and 2008. He was not held by ICE or deported after the arrests. An ICE report concluded that new federal immigration policies would have prevented Montano's release.

But the rise in traffic offenders in the deportation statistics and in some other categories worries immigration advocates, particularly because traffic stops are largely made by police, sheriff's deputies and state highway patrol officers. Local law enforcement has become more involved in immigration enforcement because of new programs that encourage it.

Officers "are using their new authority to remove as many unauthorized people from their jurisdictions as they can, and that frequently means going after traffic violators instead of serious criminals," said Muzaffar Chishti, director of the Migration Policy Institute's office at New York University Law School. The institute is a Washington-based think tank on migration.

Homeland Security Secretary Janet Napolitano noted that most people in the United States are arrested for misdemeanor offenses. But she told the AP that the percentage of felons deported will change over time.

"The more serious offenders are still in prison," she said in an interview Thursday. "We're not going to see them reflected in the numbers until we can begin to remove them."

The issue is one Obama is trying to carefully navigate in his bid for a second term as he relies on the record deportations numbers to bolster his tough-on-enforcement stance while trying to convince immigrant and Latino voters he deserves more time to get a comprehensive immigration bill through Congress.

Marshall Fitz, immigration policy director at the liberal Center for American Progress think tank, said some of the people being counted as criminals have committed traffic violations that would usually draw a traffic ticket. But when the driver can't produce a valid license, the officer pursues questions about immigration status.

Illegal immigrants caught in traffic stops often are pressured into signing an agreement to leave the United States and to pay a fine or somehow acknowledge responsibility for the traffic offense and thereby end up in the statistics as criminals even though they never went to court, Fitz said.

Kumar Kibble, Immigration and Customs Enforcement deputy of immigration, said in some cases people picked up on traffic offenses are found to have committed other crimes. But ICE attempts to categorize each deported immigrant in its statistics based on the worst crime in the person's record. ICE says the statistics involve only people who have been convicted of a crime.

Darrel Stephens, executive director of Major Cities Chiefs Association, an organization of sheriffs and police chiefs, said the data show ICE is deporting criminals. He noted that even though traffic offenses have more than doubled, they are just 7 percent of the total criminal deportations. Meanwhile, dangerous drugs and drunken driving deportations comprised 23 percent and 14 percent of the criminal deportations, respectively.

"That's a crime that people look at in a very serious way right now," Stephens said.

There are an estimated 11 million people in the country illegally, 7 million to 8 million of whom are believed to be adults.

Kibble said the numbers show his agency's system of giving priority for deportation to people who pose a public threat is working. Last year, 36,178 criminals were deported as a result of the Secure Communities program, now in place in more than 1,400 jurisdictions, up from 14 in 2008. It's expected to be in more than 3,000 jurisdictions nationally by 2013.

Secure Communities is the Homeland Security Department's system of identifying immigrants for deportation through fingerprints taken by local officers when booking people on criminal charges. The local law enforcement agencies routinely send the prints to the FBI for criminal background checks. The FBI shares the fingerprints with Homeland Security to look for potentially deportable immigrants, who can be in the country illegally or legally.